Electric coil



Aug. 7, 1928. 1,679,471

D. B. HILL ELECTRIC con.

Filed April 30, 1925 Patented Aug. 7,1928.

UNITED STATES PATENT OFFICE.

DWIGHT B. HILL, OF WINCHESTER, MASSACHUSETTS, ASSIGNOR OF ONE HALF TOHERBERT F. FRENCH, OF RANDOLPH, MASSACHUSETTS.

ELECTRIC COIL.

Application filed April 30, 1925.

This invention relates to coils adapted particularly for radio and otherhigh-frequency uses and has for its principal object to provide a coilhaving both high inductance and low distributed capacity and also littletcndcni-y to produce stray fields and which is selfsustaining withoutbeing dipped or molded in varnish or bakelite or similar materials.

The invention is particularly applicable to coils of the type in whicheach turn is shaped like a figure 8, the winding looping in onedirection (e. g. clockwise) and then crossing and looping in the reversedirection. In order to reduce the dimensions of the coils the cross-overportions of the figure 8 are ordinarily flattened out so that the twohalves of each coil are approximately semi-circular segments with theirbases together. In a coil of this kind the winding extendscircumferentially of the coil (e. clockwise), thence crosses through thecoil to another point in the circumference, thence extendscircumferentially in the opposite direction (e. g. counter-clockwise),thence crosses to another point in the circumference, and so on. In thepreferred form the winding crosses along a diametrical chord (i. e.aligned radii) first in one direction and then in the oppositedirection.

According to this invention the circumferential portions have theirboundaries (inner and outer peripheries) substantially spaced apart andsucceeding turns of the winding cross back and forth between theboundaries throughout these portions, preferably at different pointsalong the circumference in succeeding turns, thereby reducing thedistributed capacity and physically strengthening the structure.Likewise succeeding turns preferably cross at different pointsthroughout the length of the diametrical portion of the coil, wherebythe distributed capacity is reduced to a minimum throughout the entirecoil while the stray fields are at the same time largely eliminated.

For the purpose of illustration one concrete embodiment of the inventionis shown in the accompanying drawings in which Fig. 1 is an end View,and

Fig. 2 is a side view with portions broken away.

Serial No. 26,997.

In the particular embodiment chosen for purpose of illustration the coilis wound upon pins which may be withdrawn after the coil is completelywound and the windings tied or bound together in suitable manner.Tracing the uppermost winding from the end A, it extends inside pin 1,thence along the inner periphery to pin 2, thence crosses to the outerperiphery between pins 2 and 3, thence follows the outer periphery frompin 3 to pin 4, thence crosses to the inner periphery between pins 4 and5, thence follows the inner periphery from pin 5 to pin 6, thencecrosses t0 the outer periphery between pins 6 and 7, thence follows theouter periphery from pin 7 to pin 8, thence crosses to the innerperiphery between pins 8 and 9, thence passes around pin 11 at theright-hand boundary of the diametrical portion, thence crosses to theleft-hand boundary of the diametrical portion and passes around pin 20,thence crosses from the inner to the outer periphery of the lefthandcircumferential portion between pins 22 and 23, thence follows the outerperiphery from pin 23 to pin 24, thence crosses to the inner peripherybetween pins 24 and 25, thence follows the inner periphery from pin 25to pin 26, thence crosses to the outer periphery between pins 26 and 27,thence follows the outer periphery from pin 27 to pin 28, thence crossesto the inner periphery between pins 28 and 29 thence passes around pin31 and crosses .rom the left-hand boundary of the diametrical portion tothe right-hand boundary at in 0, thus completing one complete turn (twohalf turns) at pin 0.

The second turn 6 crosses from the inner periphery to the outerperiphery between pins 1 and 2, to the inner periphery between pins 3and 4, to the outer periphery between pins 5 and 6 to the innerperiphery between pins 7 and 8, to the outer periphery between pins 9and 10, thence extends from the outer periphery at pin 10 to the innerperiphery at pin 20, thence crosses to the outer periphery between pins21 and 22, to the inner periphery between pins 23 and 24, to the outerperiphery between pins 25 and 26, to the inner periphery between pins 27and 28, to the outer periphery between pins 29 and 30, and thencecrosses from the outer periphery at pin 30 to the outer periphery at pin1.

The third winding extends along the outer periphery from the pin 1 topin 2, thence crosses to the inner periphery between pins 2 and 3, tothe outer periphery between pins 4 and 5, to the inner periphery be..-:een pins (3 and 7, to the outer periphery :(.t\YCOI. pins 8 and 9,along the outer periphery from pin 9 to pin 10, thence crosses from the.outer periphery at pin 10 to the outer periphery at pin 21, thenceextends along the outer periphery from pin 21 to pin thence crosses tothe inner periphery between pins and 23, to the outer periphery betweenpins 21 and 25, to the inner periphery between pins 26 and 27, to theouter periphery between pins 28 and 29, along the outer periphery to pin30, and theme crosses to the outer periphery at pin 1.

The fourth turn 61, starting at pn l, crosses to the inner peripherybetween pins 1 and 2, thence to the outer periphery between pins 3 and4, to the inner periphery between pins and 6, to the outer per pherybetween pins 7 and 8, to the inner periphery between pins 9 and 10,thence extends from the inner periphery at pin 11 to the outer peripheryat pin 21, thence to the inner periphery between pins 21 and 22, to theouter periphery between pins 23 and 24, to the inner periphery betweenpins 25 and 26, to the outer periphery between pins 27 and 28, to theinner periphery between pins 29 and 30, and thence crosses from theinner periphcry at 31 to the inner periphery at pin 0.

The next turn 6, and every fourth turn thereafter, follows the samecourse as the first turn a except that they start from pin 0 instead ofpin 1. Likewise every fourth turn after turn 6, 0 and d respectively,follows the same course. As shown in Fig. 1 the windings cross atdifferent points along the diainetrical portion, thereby reducing thedistributed capacity in ths portion.

If desired, two or more coils may be wound together. In Fig. 1 twoseparate windings are shown, one beginning at A and ending at B, and theother beginning at C and ending at D. Starting at A one wire is wound asaforesaid up to the point where the loop L beg'ns, the winding of thefirst wire then being temporarily discontinued while a second wire iswound from D to C n the same manner and preferably though notl'iccessarily in the same direction as the first wire, and the firstwire is then looped across as shown at L and the winding continued inthe same manner and direction to the end B. The central winding CD maybe employed as a primary and the windings AL and L-B on opposite sidesof CD may be used as a single secondary. By placing the primary betweenthe two portions of the secondary the magnetic effect of the coil onadjacent devices is still further reduced. \Vhen wound as aforesaid theouter periphery of the coils appears as a s'ngle continuous unitary coilshown in Fig. 2.

After the coil is wound as aforesaid, the pins 1 to 31 may be withdrawnand the wires bound together axially of the coil by threading a cordback and forth through the spaces originally occupied by the pins.

t will of course be understood that different numbers of pins may beemployed, and that the wlrc may follow the inner and/or outer peripheryof the coil a plurality of spaces between pins instead of a single spaceas illustrated. However, the number of pins along each of the twosemicircles should be a multiple of the number of pins spanned by eachwinding before it crosses from one to the other periphery.

From the foregoing it is evident that sueceed'ng half-turns of the twocircumferential portions cross between inner and outer pe-- ripheriesthe same number of times but alternate half-turns of eachcircumferential portion cross different numbers of times. F or example,in the right-hand circumferential portion the turn a crosses four times(between pins 2 and 3, 4, and 5, 6 and 7, and 8 and 9) and likewise inthe left-hand circumferential portion; whereas in the next turn 5 thewinding crosses five times in each circumferential portion (between pins1 and 2, 3 and 4, 5 and 6, 7 and 8, and 9 and on the right-hand portionand on the left-hand portion between pins 21 and 22, 23 and 24, and 26,27 and 28, and 29 and Moreover succeeding turns cross between inner andouter peripheries at different points along the circumferential portionsor at different longitudinal lines. For example turn a (and every secondturn thereafter) crosses at lines extending parallel with the axis ofthe coil between pins 2 and 3, 4 and 5, 6 and 7, 8 and 9, 22 and 23, 24and 25, 26 and 27, and 28 and 29, whereas, turn I) (and every secondturn thereafter) crosses at lines between pins 1 and 2, 3 and 4, 5 and6, 7 and 8, 9 and 10, 11 and 12, 13 and 14, 15 and 16, 17 and 18, and 19and 20. Thus turns a, 0 etc., cross eight times in the circumferentialportions, four times on each side, and turns 6, 03 etc, cross ten times,five times on each side.

I claim:

1. An electric coil comprising a continuous winding which extendscircumferentially of the coil throughout approximately 180, thencesubstantially diametrically from side to side, thence approximately 180in the opposite direction, thence substantially diametrically in theopposite direction, and so on throughout succeeding turns, thecircumferential portions having an inner and outer periphery, thewinding cross- IOU ing back and forth between the inner and outerperipheries throughout the circumferential portions, the diametricalportions of some of the turns spanning the inner periphery and thediametrical portions of others of the turns spanning the outerperiphery.

2. An electric coil comprising a continuous Winding which extendscircumferentially of the coil throughout approximately 180, thencesubstantially diametrically from side to side, thence approximately 180in the opposite direction, thence substantially diametrically in theopposite direction, and so on throughout succeeding turns, thecircumferential portions having an inner and outer periphery, theWinding (rinsing back and forth between the inner and outer peripheriesthroughout the circumferential portions, the diametrical portions ofsome of the turns spanning the inner periphery, the diametrical portionsof other of the turns spanning the outer periphery, and the diametricalportions of other of the turns extending from inner periphery to outerperiphery.

3. An electric coil comprising a continuous Winding which extendscircumferentially of the coil throughout approximately 180, thencesubstantially diametrically from side to side, thence approximately 180in the opposite direction, thence substantially diametrically in theopposite direction, and so on throughout succeeding turns, both thecircumferential and diametrical portions having boundaries substantiallyspaced apart transversely of the axis of the coil and succeeding turnsof the winding crossing from boundary to boundary throughout bothcircumferential and diametrical portions, and a second windingelectrically insulated from the first Winding but mechanically forming alike continuation of the first Winding.

Signed by me, at Boston, Mass. this tuenty-eighth day of April, 1925.

DXVIGHT B. HILL.

